Intraocular lens

ABSTRACT

A foldable intraocular lens with an iris diaphragm ( 2 ) for covering an aniridia. The iris diaphragm can thus be based upon a natural iris. The diaphragm essentially comprises a film, printed with a pigment, provided with a sealing layers and completely embedded in the transparent lens material.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant claims priority under 35 U.S.C. §119 of GERMAN Application No.100 10 683.8 filed on Mar. 4, 2000. Applicant also claims priority under35 U.S.C. §120 of PCT/DE01/00402 filed on Jan. 31, 2001. Theinternational application under PCT article 21(2) was not published inEnglish.

This invention relates to an intraocular lens with a transparent centralarea and an iris diaphragm adjacent to it radially for correcting orcovering an aniridia.

Eye injuries often lead to injury to the iris, so there is acomparatively high demand for intraocular lenses with iris diaphragms.

Such lenses available on the market today have a two-part design with adiaphragm of black polymethyl methacrylate designed like a ring. A lensof transparent polymethyl methacrylate is secured or held mechanicallyin the opening in the diaphragm.

These lenses have proven successful in practice.

However, since these lenses have a comparatively limited flexibility, arelatively large surgical opening must be created for implantation ofthe lens in the eye, so that healing of the eye takes a relatively longtime.

In addition, it is also desirable for the optical appearance of thediaphragm of the implanted lens to approximate even more closely thenatural iris. However, it is extremely cost-intensive to use differentlycolored materials for the iris diaphragms with these known lenses. Ifinstead of this, a pigment is applied to the black iris diaphragm, e.g.,by painting or printing, there may be toxicological risks or problemswith regard to long-term stability.

U.S. Pat. Nos. 4,955,904 and 5,622,706 disclose masked intraocularlenses, where the masking serves to correct imaging defects of the eye,not to replace an iris. According to U.S. Pat. No. 4,955,904, pigmentswhich serve to form the mask may be embedded in the lens.

The object of this invention is to create an improved lens for treatmentof aniridia. unit, whereby the diaphragm consists essentially of anopaquely pigmented film which is embedded in an outer area which isconnected in one piece to the central area of the lens and is completelysheathed by transparent lens material.

The object is achieved according to this invention by the fact that thelens and the diaphragm are designed as a one-piece unit, whereby thediaphragm consists essentially of a flexible, opaquely pigmented filmwhich is embedded in an outer area which is connected in one piece tothe central area of the lens and is completely sheathed by transparentlens material, and where the multi-layer film has an inner pigmentcarrier layer and a barrier layer which completely seals and enclosesthe pigment carrier layer—even at the edges of the layer—and isresistant to diffusion of the pigments.

According to an especially preferred embodiment of this invention, thefilm may be designed in multiple layers and may have an inner pigmentcarrier layer, which can preferably be designed to be colored byprinting technology, and a barrier layer which seals and sheaths thepigment carrier layer completely—even at the edges of the layer—andmakes it resistant to diffusion of the pigments.

In this embodiment, the transparent lens material enclosing themulti-layer film serves primarily only to guarantee a good biologicaltolerability of the lens in the eye, while the barrier layer on the filmis responsible for sealing the pigments.

In addition, this embodiment offers the special advantage thatconventional water-absorbent hydrophilic materials which areconventionally used for foldable (soft) lenses can readily be used asthe transparent lens material, so that a foldable intraocular aniridialens can now be produced for the first time.

A copolymer of methyl methacrylate and 2-hydroxyethyl methacrylate ispreferably used as the transparent lens material. This materialoptimizes the foldability and water retention of the lens duringsurgical implantation in the eye and at the same time ensures thelong-term stability in the biological medium as well as the opticalquality. In addition, this material is heat-resistant and is suitablefor sterilization with steam.

In particular, if the lens material is highly hydrophilic and absorbswater, the barrier layer should preferably consist of a hydrophobicmaterial, e.g., silicone. Thus, diffusion of pigments can be reliablyprevented. In addition, silicone also remains stable even in steamsterilization of the lens.

The primary carrier film is preferably made of a heat-resistant materialsuitable for the desirable steam sterilization of the lens, such aspolypropylene and/or polyimide in particular, and is printed with acolored pattern corresponding to that of a natural iris, e.g., by screenprinting.

In addition, with regard to preferred features of this invention,reference is made to the claims as well as the following description ofthe drawings, on the basis of which the especially preferred embodimentof the lens according to this invention and its production are describedin greater detail.

The drawings show:

FIG. 1 a top view of the lens according to this invention,

FIG. 2 a sectional view according to sectional line II—II in FIG. 1, and

FIG. 3 a sectional view of a modified embodiment according to FIG. 2.

The intraocular lens illustrated in FIGS. 1 and 2 has a lens-shapedtransparent central area 1, which is connected to an opaque, essentiallyring-shaped iris diaphragm 2 on the outside radially. This irisdiaphragm consists essentially of a ring-shaped thin film 2′ which isdesigned in the manner of an iris due to pigments printed on it and ispractically opaque. This iris-like primary carrier film 2′ is sheathedwith a barrier layer 2″ which is also closed at the edges of the primarycarrier film 2′.

The entire iris diaphragm 2 is embedded in the transparent material ofthe central area 1, i.e., the central area 1 is continued toward theoutside radially in a sheathing 1′ in which the iris diaphragm 2 isembedded and whose outer edge encloses the outer edge of the irisdiaphragm 2.

In addition, haptic elements 3 may be molded onto the outer edge of thesheathing 1′, developing into the sheathing 1′ in one piece and beingmade of the same transparent material.

The primary carrier film 2′ is preferably made of polypropylene and/orpolyimide. The sealing 2″ is preferably made of silicone, and thecentral area 1 and the sheathing 1′ are preferably made of a copolymerof methyl methacrylate and 2-hydroxymethyl methacrylate.

The lens of FIGS. 1 and 2 can be produced by first printing the primarycarrier film 2′ with pigments according to the pattern of a natural irisand punching out a ring shape corresponding to an iris.

Then this finished primary carrier film 2′ is sealed with the barrierlayer 2″.

The iris diaphragm 2 produced in this way is then encased in a copolymerof methyl methacrylate and 2-hydroxymethyl methacrylate, so that afterthe cast material hardens it is in the form of a thick blank whichprojects axially and radially well beyond the iris diaphragm 2.

The lens with haptic elements 3 as illustrated in FIGS. 1 and 2 is thenproduced by machining the blank.

The finished lens is then subjected to steam sterilization and placed ina sterile salt water bath. In this way, a very flexible, foldable lenswhich retains water is created. This lens can be implanted in the eyethrough a small surgical opening.

FIG. 3 shows as an example that, in deviation from the illustration inFIG. 2, the lens may also have a curved shape.

In addition, the biconvex design of the central area 1 of the lensesshown in FIGS. 2 and 3 is given only as an example. If needed, aplano-convex or convex-concave design is also possible.

In addition, the outside edge of the sheathing 1′ may also be designedas a bead having in principle any desired bead cross sections, if thisis medically desirable.

The shape of the haptic elements 3 illustrated here is also intendedonly as an example. Other shapes, e.g., according to medicalspecifications, are readily possible. For example, the haptic elements 3may also be in the shape of eyelets.

What is claimed is:
 1. An intraocular lens having a transparent centralarea (1) as well as an iris diaphragm (2) connected thereto on theoutside radially to correct or cover an aniridia, wherein the lens anddiaphragm (2) are designed as a one-piece unit and the diaphragmconsists essentially of a flexible, opague, pigmented film (2′, 2″)which is embedded in a lens outer area (1′) that is connected in onepiece to the central area (1) of the lens and is completely sheathed bythe transparent lens material, and wherein the film has multi-layersincluding an inner pigment carrier layer (2′) and a barrier layer (2″)which completely sheaths and seals the pigment carrier layer—even at theedges of the layer—and is resistant to diffusion of the pigments.
 2. Thelens according to claim 1, characterized in that the transparent lensmaterial is hydrophilic and the material of the barrier layer (2″) ishydrophobic.
 3. The lens according to claim 1, characterized in that thepigment carrier layer is made of a film (2′) which is printed in color.4. The lens according to claim 1, characterized in that the central area(1) of the lens is arranged with an axial offset relative to the planeof the iris diaphragm (2).
 5. The lens according to claim 1,characterized in that the transparent lens material is a copolymer ofmethyl methacrylate and 2-hydroxymethyl methacrylate.
 6. The lensaccording to claim 1, characterized in that the film (2′) is made ofpolypropylene and/or polyimide.
 7. The lens according to claim 1,characterized in that the barrier layer (2″) is made of silicone.
 8. Amethod of producing a lens according to claim 1, characterized in thatto produce an iris diaphragm (2), a film (2′) is printed with pigmentsand punched out according to a natural iris and then is provided with aseal (2″) by encasing the punched-out film in transparent lens material,and a blank obtained after curing the lens material is machinedaccording to the desired lens shape.
 9. The method according to claim 8,characterized in that a film (2′) which is used to produce the irisdiaphragm (2) is pigmented by screen printing.